Tina: [Broken Access Control] letting any TinaCloud user authorize against any self-hosted site

Summary

Tina is a headless content management system. Prior to @tinacms/auth 1.1.4 and next-tinacms-azure 15.0.1, isAuthorized accepts a request-controlled clientID and asks isUserAuthorized to validate the bearer token against that selected TinaCloud app instead of the self-hosted site's configured app. An attacker with any TinaCloud account can submit the attacker's own app ID and valid token to a victim endpoint, causing TinaCloudBackendAuthProvider or an affected media authorized callback to accept the attacker's verified status across the tenant boundary. The vulnerable logic is present in packages/@tinacms/auth/src/index.ts and packages/next-tinacms-azure/src/auth.ts. Successful exploitation permits media listing, reading, upload, or deletion and, when TinaCloudBackendAuthProvider is used, GraphQL read, create, update, and delete operations on the victim's content without a victim account or victim interaction. This vulnerability is fixed in @tinacms/auth 1.1.4 and next-tinacms-azure 15.0.1.

Timeline

1. Sep 16, 2026, 8:27 PM UTCCVE published
2. Sep 17, 2026, 3:54 PM UTCCISA SSVC assessment

   Exploitation: poc · Automatable: no · Technical impact: total

3. Sep 17, 2026, 3:54 PM UTCRecord last updated

Affected versions

• tinacms tinacms

  fixed in 1.1.4

• @tinacms auth

  fixed in 1.1.4

• tinacms next-tinacms-azure

  fixed in 15.0.1

• @tinacms/authnpm

  fixed in 1.1.4

• next-tinacms-azurenpm

  fixed in 15.0.1

References 5